1. a 93% confidence interval for the average income of all Ventura County residents from a sample of 175 residents.The average income in the sample was $53,475 and the population variance is $100,000.What is the lower bound and upper bound?
2. The meanIQ for a random sample of 150 people is 100 with a sample standard deviation of 19.Construct a 97% confidence interval for the average IQ of all people.What is the lower bound?
3. If wewant to estimate the population mean IQ of all CLU students with a margin of error of 5, what sample size should be used? Assume 96% confidence level and a population standard deviation of 9.
4. Suppose we know the sample proportion of women at CLU is0.52.If we want to construct a 95%confidence interval with a margin of error of 3%how large should the sample be?